Originally Posted by till
Please do what I suggested and you wil see that your problem is solved. The reasom for this is simply a lot of spam spam or a similar incident which causes postfix to open up more connections then your mysql settings allow which causes a lot of waiting processes which then fill up your swap.
I've set the following settings in my.cnf:
max_connections = 500
max_user_connections = 500
Was there anything else you had in mind? What about postfix?